Neighbor discovery using address registration protocol over ELMI

ABSTRACT

A system and method for mapping a network to facilitating configuration is disclosed. Address registration information is appended to an enhanced local management interface message sent between devices in a network of routers and switches. A network management system for an outside network can use that information to map out the network and configure the network as needed. The address registration information includes an Internet Protocol address and an interface index. The interface index includes both slot and port number.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of and claims the benefit ofpriority to co-pending U.S. patent application Ser. No. 12/895,553,entitled “NEIGHBOR DISCOVERY USING ADDRESS REGISTRATION PROTOCOL OVERELMI,” filed on Sep. 30, 2010, which is a continuation of and claims thebenefit of priority to U.S. patent application Ser. No. 09/921,936,entitled “NEIGHBOR DISCOVERY USING ADDRESS REGISTRATION PROTOCOL OVERELMI,” filed on Aug. 2, 2001, now issued as U.S. Pat. No. 7,809,806,both of which are hereby incorporated by reference in their entirety asif set forth herein.

FIELD OF THE INVENTION

The field of the invention relates to the configuration of router andswitch networks.

BACKGROUND OF THE INVENTION

Currently, when a network management system (NMS) configures a routernetwork, the NMS cannot configure any part of the network not made up ofrouters. Any switches that connect a router from one router network to adifferent router from another router network are often not recognizableto a local area network (LAN) management system (LMS). Similarly, anyrouters connected to a switch from a switch network are often notrecognizable to the wide area network (WAN) management system (WMS) thatmanages the switch network. This separation creates a requirement thattwo separate network management systems be used to configure a crossnetwork system. Additionally, if a switch-to-switch connection isdamaged, an LMS usually cannot determine where the problem is and haslittle ability to reroute the connection around the damaged connection.The converse is true in that a WMS has difficulty determiningrouter-to-router connection damage and reroute around the connection.

In identifying switches and routers, much of the difficulty arises is inthe presence of slots and ports. A typical midrange WAN switch cancontain up to 32 slots. While two of those slots are reserved for otherpurposes, up to thirty slots are available to be filled withcommunication cards. These communication cards contain several ports.Each of these ports can create a different connection between the switchand another communication device. The number of slots and ports can behigher or lower depending upon the model. Routers have a similar set up.The lack of knowledge about which slot and which port is being used iswhat makes communication between the LMS and the switches or between theWMS and the routers difficult.

Because the LMS often has no knowledge of intervening switches, oneprior art way to set up a connection between two routers in two separatenetworks is to follow an inefficient multi-step process. First, all therouters in the first network must be set up using either a command lineinterface (CLI) at the router or by using the appropriate graphical userinterface (GUI) at the first network's LMS. Secondly, the proper switchuniversal frame relay module (UFM) to UFM frame relay connection must beestablished using a CLI at the switch or by using a WMS. Finally, a dataconnection link identifier (DCLI) between the UFM and the each externalrouter must be set up through the LMS of either network or a CLI. Asshown, this method is not very efficient and far from user friendly.

SUMMARY OF THE INVENTION

A system is described that includes a network of routers. A local areanetwork management system manages and configures the network of routers.The system also includes a network of switches. A wide area networkmanagement system manages and configures the network of switches. Aconnection connects a first router of the network of routers to a firstswitch of the network of switches. Address registration information isappended to a message sent between the first router and the first switchover the connection.

Other features and advantages of the present invention will be apparentfrom the accompanying drawings and from the detailed description thatfollows below.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and notlimitation in the figures of the accompanying drawings in which likereferences indicated similar elements and in which:

FIG. 1 illustrates in a block diagram of a router and switch network.

FIG. 2a illustrates in a block diagram of the network as seen by theLMS.

FIG. 2b illustrates in a block diagram of the network as seen by theWMS.

FIG. 3 illustrates in a flowchart the method used by the LMS to map thenetwork.

FIG. 4 illustrates in a flowchart the method used by the WMS to map thenetwork.

FIG. 5 illustrates in a block diagram the transaction between the routerand the switch.

FIG. 6 illustrates the ELMI message with the Address Registrationinformation appended.

DETAILED DESCRIPTION

A system and method are described for enabling a router and switchnetwork to be mapped by a single network management system (NMS). Theembodiments allow the NMS to map out the network by having theindividual devices append address registration information to theenhanced local management interface (ELMI) messages sent betweendevices. The address registration information information is passed backthrough the network to the NMS, which compiles the information to createan accurate map of the network. Once this map of the network iscomplete, the NMS is able to configure the network as needed anddiagnose problematic areas.

One embodiment of a router and switch network in which the addressregistration protocol could be implemented is illustrated in the blockdiagram of FIG. 1. A first local area network (LAN) 100 can consist of aLAN Management System (LMS) 101 and a given number of routers.Additional terminals can access the LAN via these routers. Theillustrated embodiment of the first LAN includes four routers: Router 1102, Router 2 104, Router 3 106, and Router 4 108. The number of routersin the network can be increased or decreased as required. Theconfiguration of these routers previously could be accessed by using theLMS 101, or at the individual router using a command line interface(CLI).

The first LAN 100, in one embodiment, could be connected, via aconnection line 110, to a WAN 120. In an alternate embodiment, thisconnection is a radio connection or some type of wireless connection. Inan additional embodiment, the connection is a serial or parallel cableconnection. The WAN 120 can consist of a WAN Management System (WMS) 121and a given number of switches. The illustrated embodiment of the WANincludes three switches: Switch 1 122, Switch 2 124, and Switch 3 126.The number of switches in the network can be increased or decreased asrequired. The configuration of these switches could be accessed by usinga WMS 121 or at the switch using a CLI.

The WAN 120, in a further embodiment, could then be connected, via asecond connection line 130 or a wireless connection, to a second LAN140. The second LAN would also consist a second LMS 141 and a furthergroup of routers. The illustrate embodiment of the second LAN includesfour more routers: Router 5 142, Router 6 144, Router 7 146, and Router8 148. The number of routers in the second LAN is not dependent on thenumber of routers in the first LAN. The number of routers can beincreased or decreased as the situation requires. The configuration ofthese routers previously could be accessed by using the first LMS 101,the second LMS 141, or at the individual router using a command lineinterface (CLI).

The way that a network management system currently views a router andserver network is illustrated in FIG. 2a and FIG. 2b . FIG. 2aillustrates how an LMS 101 views a router network. The first LMS 101 isable to access any of the routers in the first LAN 100. As illustratedin FIG. 1, the LAN 100 is connected at Router 3 106 to Switch 1 122 ofthe WAN 120. While the LMS 101 is able recognize that Router 3 106 isconnected to something, the LMS 101 is unable to distinguish what therouter 106 is connected to. In a further embodiment, Router 6 144 of thesecond LAN 140 is connected to the WAN via a connection 130 with Switch2 124, as shown in FIG. 1. As shown in FIG. 2a , the first LMS 101 isable to recognize Router 6 144. However, the first LMS is unable torecognize how Router 3 106 and Router 6 144 are connected. ThroughRouter 6 144, the first LMS 101 can access any of the routers in thesecond LAN 140. Conversely, the second LMS 141 can access any of therouters in the first LAN 100 through Router 3.

FIG. 2b illustrates how a WMS 121 currently views a network. The WMS 121is able to recognize the switches present in the WAN 120. The WMS 121can also recognize that the switches are connected to something outsidethe WAN 120. However, the WMS is unable to recognize what the switchesare connected to. This makes configuring the network and curingconnection problems difficult.

The address registration information will make it possible for a NMS todetermine what switches and routers configure the network. Oneembodiment of this method, as applied to an LMS, is illustrated by theflowchart in FIG. 3. A switch 122 in the WAN 120 appends addressregistration information to a message at block 300. In one embodiment,the message is an ELMI message. The switch 122 then sends the message toa router 106 in the LAN at block 310. The message can be sent when oneof the networks is first configured or after a change in configurationhas occurred. In a further embodiment, the message can be sent every tenminutes, or some other set interval of time, to monitor theconfiguration. The router 106 will then pass this address information onto the LMS at block 320. The LMS 101 uses this information to map outthe network at block 330. Once the network has been mapped out, the LMS101 can then configure the entire network as desired at block 340.

A converse embodiment, allowing the system to be mapped and configuredby a WMS, is illustrated by a flowchart in FIG. 4. A router 144 appendsaddress registration information to a message at block 400. Again, inone embodiment, the message is an ELMI message and the timing andfrequency of the message can be tailored to suit the circumstances. Therouter 144 sends the message to a switch 124 in the WAN at block 410.The switch 124 passes the address information on to the WMS at block420. The WMS 121 uses this information to map out the network at block430. Once the network has been mapped, the WMS 121 can then configurethe network as desired at block 440. Usually, the LMS is more familiarto the management information systems (MIS) administrators who will beconfiguring the network. Therefore, the LMS is more likely than the WMSto be used for configuration purposes.

FIG. 5 illustrates the transaction of address information betweenswitches and routers, in one embodiment. The router 106 appends addressregistration information to a message 500 being sent to the switch 122.The switch 122 appends address registration information to a message 510being sent to the router 106. Each switch contains a managementinformation base (MIB). Once the router has acquired the proper addressinformation from Switch 1 122, the LMS 101 can access the MIB in thatswitch 122. Using this information, the LMS can then access the MIB ofthe switches 124 and 126 connected to Switch 1 122. The LMS thenaccesses each of the adjacent switches 124 and 126. In this way, the LMSbuilds a map of the entire switch network of the WAN.

One embodiment of the datapacket used to send address information isillustrated in FIG. 6. An ELMI message 600 is normally sent between therouters and the switches to coordinate management of the ports andconnections of the network. Other messages can be used in place of anELMI message. Address registration information is appended onto themessage. In one embodiment, the address registration includes an addressregistration (AR) status 610, an interface index (ifIndex) 612, and anInternet protocol (IP) address 614 to facilitate the ability of anoutside NMS to map and configure the network. In a further embodiment,the ifIndex includes a port number and a slot number. In one embodiment,the AR status alerts the inquiring device what the status of the addressregistration is for the device being inquired. The AR status currentlysignals four messages. ELMI AR messages disabled on the interface,represented in this embodiment by binary 00, indicates the router/switchare talking to a device that does not support AR. ELMI AR enabled on theinterface, represented in this embodiment by binary 01, indicatesIFindex and IP address can be used to specify the link between theswitch and the router. Additionally, the AR status can indicate, in thisembodiment by binary 10, a valid IP address and Ifindex are configuredon the interface, but the user disabled exchange of IP address andIfindex with the neighbor. The user does this typically for securityreasons. Asynchronous Version status message, represented in thisembodiment by binary 11, indicates when the IP address or Ifindex ischanged on the switch side. Normally the Address Registrationinformation is exchanged at default intervals. Rather than wait for thedefault interval, this type of message indication can be sent with thenew values to take effect immediately. In an additional embodiment, afew spare bytes 616 are included in the address registrationinformation. These spare bytes can be used for error checking or if someexpansion of the information contained in the address registrationinformation is required.

In a further embodiment, the ELMI provides an infrastructure enabling anexchange of information between the routers and the WMS or switches andthe LMS. Traffic shaping information can be passed on from the router tothe WMS, which then uses that information to deduce appropriate valuesfor traffic shaping on that router's adjacent connected switch.

The method described above can be stored in the memory of a computersystem or network (e.g., set top box, video recorders, etc.) as a set ofinstructions to be executed. The instructions to perform the methoddescribed above could alternatively be stored on other forms ofmachine-readable media, including magnetic and optical disks. Forexample, the method of the present invention could be stored onmachine-readable media, such as magnetic disks or optical disks, whichare accessible via a disk drive (or computer-readable medium drive).Further, the instructions can be downloaded into a computing device overa data network in a form of compiled and linked version.

Alternatively, the logic to perform the methods as discussed above,could be implemented by additional computer and/or machine readablemedia, such as discrete hardware components as large-scale integratedcircuits (LSI's), application-specific integrated circuits (ASIC's),firmware such as electrically erasable programmable read-only memory(EEPROM's); and electrical, optical, acoustical and other forms ofpropagated signals (e.g., carrier waves, infrared signals, digitalsignals, etc.); etc.

Although the present invention has been described with reference tospecific exemplary embodiments, it will be evident that variousmodifications and changes may be made to these embodiments withoutdeparting from the broader spirit and scope of the invention.Accordingly, the specification and drawings are to be regarded in anillustrative rather than a restrictive sense.

What is claimed is:
 1. A computer-implemented method comprising: at afirst network management system comprising a processor and memory,acquiring address registration information via a first edge device of afirst network from a second edge device of a second network, the firstnetwork management system connected to and managing the first network,the first network comprising a first plurality of devices including thefirst edge device, the second network comprising a second plurality ofdevices including the second edge device, the devices of the firstplurality of devices being of a first type of device, the devices of thesecond plurality of devices being of a second type of device differentfrom the first type of device, the second network being connected to andmanaged by a second network management system separate from the firstnetwork management system, the first network management system beingindirectly connected to the second network via the first network;accessing a management information base (MIB) associated with the secondedge device using the address registration information; accessing otherMIBs using information from the MIB associated with the second edgedevice, each of the other MIBs associated with a corresponding one ofother devices of the second network; building a map of entire devices ofthe second network based on the accessed information from the MIB andthe other MIBs; and configuring the second network using the map ofentire devices of the second network.
 2. The method of claim 1, whereinthe devices of the first plurality of devices are switches and thedevices of the second plurality of devices are routers.
 3. The method ofclaim 2, wherein the first network is a wide area network (WAN) and thesecond network is a local area network (LAN).
 4. The method of claim 1,wherein the address registration information comprises an interfaceindex associated with the second edge device.
 5. The method of claim 4,wherein the interface index comprises a slot number from which a messagewas sent to the first edge device, the address registration informationbeing appended to the message.
 6. The method of claim 4, wherein theinterface index comprises a port number from which a message was sent tothe first edge device, the address registration information beingappended to the message.
 7. The method of claim 1, wherein the addressregistration information comprises an Internet Protocol (IP) address. 8.A system comprising: a first network management system connected to andmanaging a first network that includes a first plurality of devices, afirst edge device of the first network being connected to a second edgedevice of a second network that includes a second plurality of devices,the devices of the first plurality of devices being of a first type ofdevice, the devices of the second plurality of devices being of a secondtype of device different from the first type of device, the secondnetwork being connected to and managed by a second network managementsystem separate from the first network management system, the firstnetwork management system being indirectly connected to the secondnetwork via the first network, the first management system comprising aprocessor and memory and being configured to: acquire addressregistration information via the first edge device from the second edgedevice; access a management information base (MIB) associated with thesecond edge device using the address registration information; accessother MIBs using information from the MIB associated with the secondedge device, each of the other MIBs associated with a corresponding oneof other devices of the second network; build a map of entire devices ofthe second network based on the accessed information from the MIB andthe other MIBs; and configure the second network using the map of entiredevices of the second network.
 9. The system of claim 8, wherein thedevices of the first plurality of devices are switches and the devicesof the second plurality of devices are routers.
 10. The system of claim9, wherein the first network is a wide area network (WAN) and the secondnetwork is a local area network (LAN).
 11. The system of claim 8,wherein the address registration information comprises an interfaceindex associated with the second edge device.
 12. The system of claim11, wherein the interface index comprises a slot number from which amessage was sent to the first edge device, the address registrationinformation being appended to the message.
 13. The system of claim 11,wherein the interface index comprises a port number from which a messagewas sent to the first edge device, the address registration informationbeing appended to the message.
 14. The system of claim 8, wherein theaddress registration information comprises an Internet Protocol (IP)address.
 15. A non-transitory computer-readable storage medium storinginstructions that, when executed by a processor, cause the processor toperform operations at a first network management system comprising aprocessor and a memory, the operations comprising: acquiring addressregistration information via a first edge device of a first network froma second edge device of a second network, the first network managementsystem connected to and managing the first network, the first networkcomprising a first plurality of devices including the first edge device,the second network comprising a second plurality of devices includingthe second edge device, the devices of the first plurality of devicesbeing of a first type of device, the devices of the second plurality ofdevices being of a second type of device different from the first typeof device, the second network being connected to and managed by a secondnetwork management system separate from the first network managementsystem, the first network management system being indirectly connectedto the second network via the first network; accessing a managementinformation base (MIB) associated with the second edge device using theaddress registration information; accessing other MIBs using informationfrom the MIB associated with the second edge device, each of the otherMIBs associated with a corresponding one of other devices of the secondnetwork; building a map of entire devices of the second network based onthe accessed information from the MIB and the other MIBs; andconfiguring the second network using the map of entire devices of thesecond network.
 16. The non-transitory computer-readable storage mediumof claim 15, wherein the devices of the first plurality of devices areswitches and the devices of the second plurality of devices are routers.17. The non-transitory computer-readable storage medium of claim 16,wherein the first network is a wide area network (WAN) and the secondnetwork is a local area network (LAN).
 18. The non-transitorycomputer-readable storage medium of claim 15, wherein the addressregistration information comprises an interface index associated withthe second edge device.
 19. The non-transitory computer-readable storagemedium of claim 18, wherein the interface index comprises a slot numberfrom which a message was sent to the first edge device, the addressregistration information being appended to the message.
 20. Thenon-transitory computer-readable storage medium of claim 18, wherein theinterface index comprises a port number from which a message was sent tothe first edge device, the address registration information beingappended to the message.